Improvements in or relating to an optical projecting device with a semi-automatically operated transparency changer

摘要

810,692. Optical projection apparatus. LEITZ, G. m. b. H., E. Nov. 27, 1956 [Nov. 28, 1955],SP /SPNo. 36224/56. Class 97(1) Optical projection device comprises a transparency changer, a transparency tray having side walls for laterally retaining the transparencies when the tray has been detached such that side wall adjacent the projecting device is of substantially less height than the transparencies, and means are provided for lifting at least one transparency such that its bottom edge is clear of the top of said adjacent wall, the transparency changer having means for moving the lifted transparency across the top of the side wall adjacent the projector, out of the tray into projecting position, and back again into the tray after viewing. As shown, a projector device with a slide changing mechanism as described in Specification 707,779 has a tray 10 with slideretaining compartments between walls 37, and a slot 49 in the base such that when the tray is in contact with the projector by resting upon plate 9, the riser element 42 projects through the slot 49 to lift the slide, adjacent its apex clear of the side will The slide is delivered to and returned from the projecting position in the manner described in the above mentioned Specification, and the tray is advanced a distance equal to that between adjacent transparencies by means of a toothed wheel 25 co-operating with a rack 40 on the tray: